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Mechanical Engineering Commons

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Mechanical and Aerospace Engineering Faculty Research & Creative Works

Series

1977

Articles 1 - 4 of 4

Full-Text Articles in Mechanical Engineering

Studies Of Vibrational Surface Modes In Ionic Crystals. I. Detailed Shell-Model Studies For The Unrelaxed (001) Face Of Seven Crystals Having The Rocksalt Structure, T. S. Chen, F. W. De Wette, G. P. Alldredge Jan 1977

Studies Of Vibrational Surface Modes In Ionic Crystals. I. Detailed Shell-Model Studies For The Unrelaxed (001) Face Of Seven Crystals Having The Rocksalt Structure, T. S. Chen, F. W. De Wette, G. P. Alldredge

Mechanical and Aerospace Engineering Faculty Research & Creative Works

We present a comprehensive, unified account of the lattice dynamics of unrelaxed (001) faces of seven crystals having the rock salt structure, three of which have an absolute gap between the acoustical and optical bulk bands (RbF, RbCl, and NaI) and four of which have overlap between these bulk bands (NaF, NaCl, LiF, and MgO). The results are obtained from calculations of the normal modes of a thin crystal film in which the ionic interactions are described by the rigid-shell model. An outline of the formulation of the shell model for the film is given, and the rapid convergence of …


Multiple High Voltage Output Dc-To-Dc Power Converter, Don Cronin, Bertrand F. Farber, Hartmut K. Gehm, Daniel S. Goldin Jan 1977

Multiple High Voltage Output Dc-To-Dc Power Converter, Don Cronin, Bertrand F. Farber, Hartmut K. Gehm, Daniel S. Goldin

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Disclosed is a multiple output DC-to-DC converter. The DC input power is filtered and passed through a chopper preregulator. The chopper output is then passed through a current source inverter controlled by a squarewave generator. The resultant AC is passed through the primary winding of a transformer, with high voltages induced in a plurality of secondary windings. The high voltage secondary outputs are each solid-state rectified for passage to individual output loads. Multiple feedback loops control the operation of the chopper preregulator, one being responsive to the current through the primary winding and another responsive to the DC voltage level …


Mixed Convection Across A Horizontal Cylinder With Uniform Surface Heat Flux, A. Mucoglu, T. S. Chen Jan 1977

Mixed Convection Across A Horizontal Cylinder With Uniform Surface Heat Flux, A. Mucoglu, T. S. Chen

Mechanical and Aerospace Engineering Faculty Research & Creative Works

No abstract provided.


Optimal Cantilever Dynamic Vibration Absorbers, R. G. Jacquot, J. Earl Foster Jan 1977

Optimal Cantilever Dynamic Vibration Absorbers, R. G. Jacquot, J. Earl Foster

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This work considers the use of a double-ended cantilever beam as a distributed parameter dynamic vibration absorber applied to a single-degree-of-freedom system in the presence of sinusoidal forces. The problem is analyzed exactly and by an energy approach using a single mode approximation for the cantilever beam. The results for both techniques compare favorably and damping is introduced in the form of a complex beam modulus. Optimal tuning and optimal damping parameters are found for a given ratio of absorber mass to main mass. © 1977 by ASME.